UP 844 vs N&W J611

Mark, I tried to give you an out in a post above, but you said you did not agree that "power output at the drawbar might be the same with crappy fuel vs. good fuel in equivilent engines."

 

This is where your empiricism is failing you.

And (as we've been saying) it makes absolutely NO DIFFERENCE what fuel I used to make that steam.

(Oh, and of course no offense taken).

You guys that are citing comparisons with dragsters, BTU values of lignite versus coal, etc. are getting way off track. You are making all this much more complicated than it really is.

 

If a steam locomotive is being fired with lousy coal, it will simply take more of it to achieve the rated boiler pressure and steam output. That's literally all there is to it.

 

A first-hand, personal experience...

If we are running NKP 765 with good coal (more than 12,500 BTU/lb., <6% ash and a fusion temperature of more than 2,600 degrees F) we can stretch a 22-ton load of coal to last 300 miles. That is 13.6 miles per ton. With a coal cost of $200 per ton, that's $14.70 per mile.

 

We have occasionally had to use coal that did not meet these specs. Using cheaper coal that had only 11,200 btu per pound and was almost 8% ash, 22 tons barely lasted 180 miles. That's only 8.1 miles per ton. At $170 per ton that's 20.98 per mile.

 

It actually costs MORE to run the cheaper coal!

 

This calculation does not apply to the western railroad's coal supply situation. The better coal from West Virginia, Kentucky, Illinois, etc. would involve huge transportation costs to get it to the west. That would skew the numbers drastically in favor of using the locally available Lignite.

 

As far as performance and power were concerned, we could maintain full rated boiler pressure with BOTH coals, so the engine performed just fine on both coals. But it took a lot more of the bad stuff to make the distance than with the good coal.

Now darn it Rich, we were obviously NOT getting thru to Mark, so I began to enjoy discussing Fuel Dragsters.

Well, Rich provides some hard, empirical data, so I will chew on it a while. If I decide you guys are right, you will never hear from me again!!!!!!  (probably not!)

At the end of the day you either get boiler pressure and steam output or you don't...seems pretty simple. The fuel used is simply a BTU source that facilitates that goal. 

 

Jeff C

Closest fuel could be the least expensive fuel, regardless of the BTU content.

Boiler design is based on the fuel used, lower BTU fuel requires a larger furnace to burn an equivalent number of BTUs.

 

One advantage of quality fuel is maintenance down time. You could have longer run times between maintenance outages. In the electrical power business we called that EAF (Equivalent Availability Factor). The greater that number the greater the power production capability. In railroad language it might be: "out of 8,760 hours in the year, what percent of of that time are you not in the shop or broke down?"

 

I'd say that maximizing run time is one of the main aspects that had N&W still running steam after nearly all other railroads gave in the diesels. 

 

Ergo: N&W 611 > UP 844

Ok ok, I am a beaten man! But I have this nagging feeling that an NP Challenger, burning NP Rosebud lignite, would not have pulled the APL stack train, 7965 tons +/-, over Archer Hill, at the same speed as good old 3985. I own a Z8 and want to believe it's every bit as "macho" as anyone else's Challenger, but just way down deep don't believe it could turn in the same performance. Now the Z8 has 260 psi, the 3985 has 280 psi.For the tractive effort enthusiasts, the Z8 has a higher tractive effort, but that's not really the issue here.   But I will go away quietly into the night! 

If I decide you guys are right...

"Decide" if we're right?? I'm afraid you don't get that option. BUT...you can decide whether or not you want to believe us.

Exactly, it is all about Horse Power once the train is moving! The UP 3900 class had HIGHER horse power that the NP Z Class locomotives, because the NP was into "dragging" freight do to the terrain that went through, i.e. LOTS of curves. The UP, however was into SPEED, thus the higher boiler pressures and higher steam temperatures, which equal HIGHER HP.

Overheard at Spencer;  Ed Dickens with Scott Lindsay looking at the running gear of the Mighty J. " Wow, man, if I could only have those roller bearing rods on our 800!"

Oh no, that would be just great, after what the dear leader did to the boiler & tender on "his 844"!

Don't let that man anywhere near the "J"...good grief it would never operate!

How about we just have a technical discussion concerning the UP 800's with roller bearing rods? WHAT A MACHINE THAT WOULD BE ! !

The coal in the Eastern United States was laid down by plant life that existed in the shallow seas as the Iapetus Ocean closed during the formation Pangaea 300 million years ago. What is now Europe, Africa, and North America collided when the Iapetus Ocean closed and Pangaea formed. The Appalachian Mountains were thrust 30,000 feet and all the plant life that was deposited in the shallow seas was compressed and heated to form the anthracite and bituminous coal today. Yep, all that eastern coal is from the plants that existed 400-300 million years ago! Geologic time is why these coal deposits have high energy content. However, because these coal deposits formed in Iapetus Ocean as it closed, they are high in sulfur content. Coal that is derived from ocean plant life is higher in sulfur than coal derived from plants in fresh water. The water of the ocean is higher in sulfates. Thus, the high btu content of the eastern coal deposits comes with a price: acid rain.

 

The coal of the Western United States was deposited during the Cretaceous to early Tertiary, roughly 140 to 60 million years ago. During this time a shallow sea, called the Western Interior Seaway, existed from the Gulf of Mexico to the Arctic Ocean, bisecting the land area of the North American continent. The plant life that lived and died in this sea is the coal of today. Towards the end of the Cretaceous, two oceanic tectonic plates collided with North America. These plates were the Kula and Farallon Plates. The collision between these plates gave rise to the Rocky Mountains. Today, the Rocky Mountains occupy the same area as the Western Interior Seaway. Kula is nearly completely subducted; a small piece of it is under the Bearing Sea. The Juan de Fuca Plate and the Cocos Plate are remnants of the Farallon Plate and continue to subduct, while the San Andreas Fault connects the two. The Western United States coal is much younger than the coal of the Eastern United States and has not had the geologic time to compress; hence, it has less energy content. However, since Western United States coal was formed from waters of much less salinity it has much less sulfur in it and as such is better for the environment.

 

A coal-fired plant designed to burn Appalachian coal must be modified to remove SO₂ at a cost estimated be around $190 / KW. If it switched to burning Powder River coal, the cost dropped to $50-60 /KW. The reason why it is cheaper to operate the 765 off of eastern coal is that all the sulfur is released to the atmosphere. However, coal plants cannot release all the acid (SO₂ is a potent Lewis Acid) into the atmosphere. Hence BNSF and UP transport Powder River coal all over the Nation whereas eastern coal is not as popular to fire coal plants.

Rich,

 

Thanks for a real world answer that makes common sense.

 

Larry

What about the engineer/ fireman interviewed on the Pentrex Bigboy video?

 

He said they ran out of coal and grabbed some old ties from the side of the track and put them into the firebox. The draft sucked it out of their hands and into the firebox.

 

How good of fuel are old ties?, premium, nitro, e85?.....................

Is the chart shown here on page 6 not correct?

https://www.asme.org/getmedia/...-Steam-Locomoti.aspx

 

Exactly, it is all about Horse Power once the train is moving! The UP 3900 class had HIGHER horse power that the NP Z Class locomotives, because the NP was into "dragging" freight do to the terrain that went through, i.e. LOTS of curves. The UP, however was into SPEED, thus the higher boiler pressures and higher steam temperatures, which equal HIGHER HP.

 

 But, Jack, the NP ran their Challengers at 60 mph all the time, all across Montana. Yes, they hit the Rockies west of Livingston, but east, Billings-Livingston-Glendive was much more favorable Challenger territory.  And the NP Challengers had 152.3 sq ft of grate to compensate for, ok, I will say it, the low BTU content of their fuel, AND the NP locomotive had a larger evaporative surface, 7854 sq ft vs the UP Challenger's 6957. Don't believe I have ever seen a photograph of an NP Challenger handling a train bigger then 5000 tons. Can the UP's (now I am presuming here) Challenger's superior performance all be attributed to a 20 lb psi difference (260 vs. 280)? And I will bet a D&RGW 4-6-6-4 would have beat the pants off a UP Challenger.......in fact, the Rio Grande was assigned some redirected UP Challengers during WW II by the War Production Board. The Rio Grande kicked the UP Challengers out as soon as the war ended, as too puny........and the Rio Grande Challengers had 255 psi. The Rio Grande did not buy their Challengers for drag freight service, they bought them to out run competitor UP for fast freight business, Grand Junction-Salt Lake City. The NP locomotive at least on paper looks like it should be equivalent, or maybe even superior to the UP locomotive.  But I don't think it was. So, why not?     ..........maybe fuel?   BTW, you note higher steam tempertures as a source of greater power; where did the higher temperature come from?

Increased amount of superheater units, produces longer time for the steam spent within those units. Thus, higher steam temps into the valves.

Matt A.

 

No, you're not reading things incorrectly.  What you're reading is incorrect.

 

The 275 lbs curves (DBHP and DBP) in the ASME publication are about right.  However, it's a theoretical curve calculated using the Baldwin method. It's not based on actual test results.  The 300 psi curves are not accurate at all.  N&W did not publish such curves in its test reports.   I have no idea how they were actually developed.  I've been able to approximate them using a variety of incorrect methods, but that's about it.  For example, the 300 psi DBHP curve resembles the Baldwin-developed INDICATED HP curve up to about 80 mph, but is off at 90 and 100 mph.  How this mess got through the editing process for an ASME-sponsored booklet is a mystery to me.

 

I think that both camps are "partly right", and here is why....

When an indicator card was taken on a test, the "fatter" the area of the card, the higher the Cylinder HP. This can only occur if the engine is being operated at "full cutoff", in effect, testing the ultimate capability of the boiler to make sufficient steam. As an example, the NYC Niagaras recorded 5070 drawbar HP at 62.4 mph. That means that the boiler was able to supply sufficient steam to the cylinders to make the "fattest" indicator card until a track speed of 62.4 mph was reached. Of course, no reasonable person would run a locomotive in that manner, but the test was made to show what the boiler, and the auxiliaries such as the stoker and feedwater heater, could do under maximum boiler output conditions. The N&W J peak DBHP occurred at about 41 mph. The boiler was excellent, but the J had both larger cylinders and smaller drivers, so the speed at which it developed its peak HP would necessarily be lower. The Niagara boiler maximum evaporation was greater than the N&W J, in spite of the use by N&W of somewhat better coal. (The NYC tests were run with coal of 13,600 BTU's/lb. N&W used coal over 14,500 BTU's/lb.) The difference between the 41 mph peak horsepower speed of the J and the 62.4 mph peak horsepower speed of the Niagara indicates that the Niagara boiler had to generate about 500 additional HP to overcome wind resistance and friction at 62 mph vs at 41 mph. And the J was streamlined which may have given the engine even better wind resistance than the AAR formulae recognizes.

It is also true that, if a crew can maintain rated boiler pressure, the use of an inferior fuel becomes an economic issue. BUT, it also could mean that the engineer had to shorten the cutoff or run out of steam if a maximum effort was required, so that engine would be slower on a grade or in its balancing speed on level track.

That is why steam locomotives were specifically designed differently for each railroad. They were application rated, unlike diesels.

Feltonhill-

The curve that I referred to appeared in "Railway Mechanical Engineer", December 1946, page 657. It is captioned "Comparative drawbar-pull-speed chart for the Class J locomotives showing the influence of the change in boiler pressure." The curves are titled: "Calculated Drawbar Pull and Horsepower Curves", Class J Locomotives." The drawbar HP at 100 mph for 275 psi is about 2980. the  curve for 300 psi is 3150. I also have another copy of that curve with more gridlines. I do not have a source document for it but it is credited to "N&W Ry. Co. M.P. Dept, Roanoke, VA and dated April 29, 1946."

A close reading of the Fry NP book mentions the design approach for at least the A-3 class, in that they were designed with limited cutoff, and that this was later  corrected.

It is a little bit more off topic, but the Fry book also has the dyno test results for the famous Timken Four Aces!

With regard to cutoff, there was a reason why engineer's referred to the shortest running cutoff as "the company notch". It was much more efficient in the use of coal and water, and it is where the superheater really added to the boiler's efficiency. 

I'd believe that, it makes sense. With the J's 70" drivers as compared to the Niagara's 79" drivers the "J" would peak at approx. 41mph as stated while the Niagara being a higher stepping locomotive was just getting into it at 41mph.  But the J's were built for accelerating the trains back up to speed quickly in the Mountainous terrain that the N&W operated in, and they did just that and did it well.  Once the J's were bumped to freight service they posted some staggering numbers for tonnage.

Could you imagine?!  That would indeed be interesting.

OK, good point. I never understood why the UP never went with light weight roller bearing equipped rods on their 800 class locomotives. I believe the UP had a roller rod equipped Pacific and a Mountain, for the 49er Passenger train consist.  Apparently, they had such success with the plain bearing pi-grease lubricated rods, the felt no need for roller bearings. I do know that the FEF-2 and FEF-3 locomotives exceeded 100 MPH regularly for quite long periods of time, on the Nebraska "Overland Route".

As for light weight roller rods, Santa Fe must have thought they were worth while after the war.  And As for running a coal slurry of any kind in an internal combustion engine....you'd have to be smoking the front lawn!  Your lube oil would be totaled by contaminates like yesterday, even with high tech filtration and chemical intervention.

Who knows what GE was thinking....and if EMD is actually trying this, they're crazier than a box of genetically enhanced peach fuzz.  I'd rather pour sand in the oil sump of my top fuel dragster!   

I have this nagging feeling that an NP Challenger, burning NP Rosebud lignite, would not have pulled the APL stack train, 7965 tons +/-, over Archer Hill, at the same speed as good old 3985. I own a Z8 and want to believe it's every bit as "macho" as anyone else's Challenger, but just way down deep don't believe it could turn in the same performance. Now the Z8 has 260 psi, the 3985 has 280 psi.For the tractive effort enthusiasts, the Z8 has a higher tractive effort, but that's not really the issue here. 

 

The NP Yellowstones, Challengers and Northerns had ample grate areas to burn enough Rosebud coal to provide needed BUTs and keep steam pressure up.  And yet, as far as I know,  no NP steam locomotive was ever recorded producing 5000 drawbar Horsepower or more.  How could those big, modern locomotives not match the recorded performance of similar sized engines?

 

It is a horsepower issue!  And there is one element of NP steam and Rosebud coal that seems to have flown below the radar in this discussion and others.  This design issue may have had the largest impact on the performance of NP steam.

 

It is related not the the low BTU value but to the low density of Rosebud coal.

 

Rosebud coal is light weight.  A locomotives designed for bituminous coal sucked Rosebud coal off of the grates under heavy draft.  The NP did two things to prevent Rosebud coal from being pulled out of the fire box before it was consumed.  First, they developed grates with very small air openings. The NP also used exhaust nozzles designed to NOT produce too heavy a draft under wide open throttle.  The NP nozzles along with the special grates did address the problem of pulling low density Rosebud coal out of the firebox before it was burned.  But the nozzles resulted in high back pressure under full throttle.

 

High back pressure means that significant energy (heat! for HW ) was left in the steam when it left the cylinders of the NPs biggest locomotives.

 

The SP&S Challengers and Northerns were built as oil burners and as add-ons to NP locomotive orders.  While their fuel was different the more significant question may be did they have NP exhaust nozzles?

 

 

 

 

 

 

 

By your statements, I will assume that you have at least a Masters Degree in Mechanical Engineering, if not a Doctorate, with EXTENSIVE experience in combustion processes on both four stroke cycle AND two stroke cycle, medium speed compression ignition engines.

You can run "heavy fuels" in these engines to whatever degree you're willing to put up with the idiosyncrasies, I know Espee did it (and maybe UP too) back in the day when Bunker C was considered a near waste product.  And yes, you can make "oil" out of coal...at least as far back as the Third Reich.  They are all liquid fuels. Golly, Rudolf Diesel even thought of running his fledgling machine on peanut oil!   Coal slurry, if it really IS coal  slurry, has no place in an internal combustion engine.

And even if somehow you could make it work for more than ten minutes, why would you want to do such a thing?  Especially after reading about the various fuel qualities in this thread !  It might be OK in some external combustion machine....but keep that jive away from my 645 !........As for the roller rods, I'm told that AT&SF raised their speed limits on the 2900s and 3776 class Northerns after the application of such rods up to 100 MPH.   Makes you wonder if this may have been more related to possible balance issues, rather than just "wear and tear". It's too bad the 5011 class didn't get those roller rods....cuz they're just sooooo sexy !  

I was at GE when a locomotive was converted to burn pulverized coal. The impetus for this was a grant available to a railroad or manufacturer from either the Dept of Transportation or the Dept. of Defense, available to modify an existing diesel engine in a locomotive to burn pulverized coal and establish what the HP would be. I believe also that N&W was involved. GE was awarded sufficient grant funds and was able to modify one of their test units. The unit was painted white!

It was technically interesting, to say the least. The pulverized coal would quickly settle in the fuel tank, so GE had to apply agitators to keep the coal and water as a mixture. The injectors were modified with diamond tips, since the use of anything else wore out the tips in a few hours. The GM who led this project told me that a woman's rouge had the consistency of "moon rocks" when compared with the average size coal particle in the slurry. He also told me that this pulverized coal was very explosive and required special handling until it was mixed with the water. (You might recall that Rudolph Diesel ran his first engine with pulverized coal, and it exploded and almost killed him.)

I recall that GE attended a meeting with the Dept, and was second in line after Caterpillar told the Dept. representatives that no more than 1500 HP was possible burning this mixture in a railroad diesel engine. GE entered the meeting with engineering test traces of 4500 GHP........

Hudson5432,

 

Thanks for the RME reference.  I just checked the curves and they are taken from the test report for the 275 vs 300 psi tests and appear to be accurately transcribed.  The 300 ppis cure is vastly different from that found in the ASME booklet.  However, the extensive note that appeared in the test report version of the graphs is missing.  This explains that the curves were theoretical and were calculated using the Baldwin method.  It's  important to note that the curves do not reflect not actual  readings, but are estimated using a popular method developed by BLW and widely used in the industry.

 

In addition, the boiler pressure comparative tests were limited to a nominal speed of 40 mph by curvature, and speeds were maximum allowed over that portion of the railroad.  Essentially they were constant speed tests.  The J tested (#604) developed a maximum reading of 5028 DBHP at 41 mph.  However, because these were comparative economy tests, this reading was not an all-out maximum reading, nor was it reflective of what conditions would have been at 45 mph or higher.  We simply don't know what the full-bore maximum DBHP curve for a J looks like because such a test was never run.  Frustrating, but that's the way it's turned out.

 

I don't agree that the Niagara's evaporation was greater than the J.  In the Niagara test report an equivalent evaporation figure of about 117,000 lbs/hr is shown.  During the 1945 tests for the J, a total evaporation of about 99,900 lbs/hr was recorded.  Equivalent evaporation and total evaporation are not the same thing.  The maximum recorded total evaporation for the Niagara was about 86,000 lbs per hr, somewhat less than the J. 

Hudson....yeah, I remember that GE contraption, but not with the same detail you have.  I heard it was going to be run with a Diesel fuel /  coal mix....and not quite as fine as you describe.  Water and coal ?   Wonder what kind of compression they were running, and what on Earth was used for cylinder lube ???  An obvious dead end, for which we can all be thankful.  UP ran #80 for brief periods with a coal / Diesel fuel / Bunker C mix back in the mid '60s. The particulate matter ate the 5000HP GE Turbine a bunch worse than any problems encountered with Bunker C alone.  Think I'm gonna run Diesel in my 645, coal in my steamer (no Lignite!) and put a pill in my 736....Huzzah !

In the testing done between the Pennsy's T1 and the J in June of 48' the 604 actually posted a max. dbhp reading of 5,250 at 41mph.

Ted Hikel  -- Excellent and illuminating contribution! I bet it was the back pressure that crimped Northern Pacific horsepower. And wonder if the exhaust nozzle of SP&S #700 is crimped?

With those 70 inchers just waiting to bite into some heavily sanded rail...it really gets you to thinking about what these girls could do in freight service at the end. We've had at least one thread here in the last three years (cuz I started it!) on this subject, but putting this grand machine on heavy tonnage just seems to bring out her inner stonk !  You wouldn't expect her on Y6 tonnage in the mountains, but nearly anywhere else...look out!  Here is where you could couple on enough resistance to really work the boiler and machinery to their max potential.  Also makes you wonder what we could do today through computer modelling. We've got enough base info, AFAIK, to build a pretty good one.

The J's when moved to freight were rated Portsmouth to Williamson at 5,500 tons although that much tonnage was never hauled, but on January 6,1958 a "J" handled 198 empties (4,950) tons from Portsmouth to Williamson.  Also from Williamson to Portsmouth the J's were rated at 11,500 tons, as such on February 28,1958 a J handled 150 loads ( 12,297 tons!) from Williamson to Portsmouth.  The J's were indeed race horses and mules all in one.  

 

I would love to get some modern numbers on the 611 once she's completed, the data would be very interesting to say the least.

5,500 tons east and 11.500 tons west.

 

Shows you how much effect even a little grade has on locomotive performance.

At the end of NYC H-10 Mikado operation in IL, the late Ray Curl left us with some trailing tonnages. from my memory, the heaviest train pulled by an H-10, which had a booster, was almost 12,000 tons.

However, I am equally positive that the N&W J would pull a train of that size much faster.

 

CWEX, can you provide the reference for the quoted DBHP of the N&W J, and the testing on which that figure is based?

 

feltonhill-I reviewed the Niagara test report. It closely follows the ASME Test Codes. I have the 1923 edition, and the codes were withdrawn in 1949. In the dynamometer test 46-53 run on 7/23 46, results are as follows:

-Equivalent evaporation per hour, feedwater heater only   12,110 lb

-Equivalent evaporation per hour boiler only          90,320 lb

-Equivalent evaporation per hour superheater only          15,200 lb

-Equivalent evaporation per hour, combined          117,630 lb.

I think that anyone would agree that the superheater and the feedwater heater are central to the operation of the boiler, and in fact the superheater is integral to the boiler.

The above figures are actual from over-the-road testing.

The Summary of this Niagara Test Report also references the static boiler testing of S-1A #6000 at Selkirk, NY. This was a "boiler only" test, as the engine was instrumented and in a roundhouse stall. I quote the report as follows:

"...during the "K" series conducted with locomotive 6000 at Selkirk, the firing rate was increased from 15,000 pounds to 17,000 pounds of dry coal per hour, or 13.3 percent; the combined equivalent evaporation was only increased from 147,000 pounds to 157,000 pounds per hour, or 6.8%."

On this test the boiler was not limited in its steaming capability by the cylinder volume, the cutoffs used, the maximum speed, etc. as would occur in over-the-road testing.

 

The book by Afred Bruce, titled, "The Steam Locomotive in America", quotes a rated evaporation for "a modern 4-8-4 locomotive" tested in late 1945 as 136,000 lb. per hour.

 

Based on the reports for the Niagara and the N&W J, both engines were "overfired" to a degree during their testing, and firing rates were in the 121-125 lb of coal per sq foot of grate per hour. The Niagara developed a higher drawbar HP than the J at a slightly lower firing rate. The use of 4" flues on the Niagara gave it the capacity to be overfired with better boiler performance and efficiency. 

Edited 7/10/14 PM - I looked at the figures this evening after I got my laptop unpacked and there are some firing rates that exceed 120 lbs/SF grate area.  I was confusing unit evaporation/sf of direct heating surface, while taking the risky approach of relying on my not-so-hot memory.  I made this mistake: figures of 120-125 lbs evaporation per SF of direct heating surface is a relatively high figure, indicating that the boiler is being pushed fairly hard.  However, this is not what Hudson5432 stated.  The same figure used as a firing rate in lbs/SF of grate area isn't so significant, at least IMO.  PRR used firing rates in teh range of 315 lbs/SF grate for the M1 tests in the mid-1920s.  As near as I can tell after reviewing the test data, the J was not extended fully during the August 1945 tests.  They were designed to measure the relative economy of raising the boiler pressure, not determining absolute maximum DBHP.